Pull request 1861: 4923-gopacket-dhcp vol.1

Merge in DNS/adguard-home from 4923-gopacket-dhcp to master

Updates #4923.

Squashed commit of the following:

commit edf36ce8b1873272c3daebe8cc8f8132793aac44
Merge: a17513d3e 123ca8738
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Jun 22 14:14:39 2023 +0300

    Merge branch 'master' into 4923-gopacket-dhcp

commit a17513d3e0a9e596d56444dfa46478eee15631de
Merge: f04727c29 994906fbd
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Wed Jun 21 17:49:09 2023 +0300

    Merge branch 'master' into 4923-gopacket-dhcp

commit f04727c29eaf22f9eb53f3aa33d42d00e177b224
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Jun 20 15:42:31 2023 +0300

    home: revert clients container

commit c58284ac6b5b2274da5eed2e853847d757709e5b
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Mon Jun 19 21:10:36 2023 +0300

    all: imp code, names, docs

commit 4c4613c939e1325d11655822d9dbc3f05a6d203c
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Tue Jun 13 18:51:12 2023 +0300

    all: imp code

commit 0b4a6e0dd561d9b7bb78dea21dcc947bcd0bd583
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Wed Jun 7 18:40:15 2023 +0300

    all: imp api

commit 0425edea03d6ca0859657df683bef6ec45bfc399
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Mon Jun 5 15:57:23 2023 +0300

    dhcpsvc: introduce package

commit 5628ebe6cccf91e2c48778966730bcbbe9e1d9f2
Author: Eugene Burkov <E.Burkov@AdGuard.COM>
Date:   Thu Jun 1 17:49:12 2023 +0300

    WIP
This commit is contained in:
Eugene Burkov 2023-06-22 14:18:43 +03:00
parent 123ca87388
commit f40ef76c79
10 changed files with 324 additions and 104 deletions

View File

@ -25,11 +25,8 @@ func (s *bitSet) isSet(n uint64) (ok bool) {
var word uint64
word, ok = s.words[wordIdx]
if !ok {
return false
}
return word&(1<<bitIdx) != 0
return ok && word&(1<<bitIdx) != 0
}
// set sets or unsets a bit.

View File

@ -249,31 +249,30 @@ func (c *dhcpConn) buildEtherPkt(payload []byte, peer *dhcpUnicastAddr) (pkt []b
func (s *v4Server) send(peer net.Addr, conn net.PacketConn, req, resp *dhcpv4.DHCPv4) {
switch giaddr, ciaddr, mtype := req.GatewayIPAddr, req.ClientIPAddr, resp.MessageType(); {
case giaddr != nil && !giaddr.IsUnspecified():
// Send any return messages to the server port on the BOOTP
// relay agent whose address appears in giaddr.
// Send any return messages to the server port on the BOOTP relay agent
// whose address appears in giaddr.
peer = &net.UDPAddr{
IP: giaddr,
Port: dhcpv4.ServerPort,
}
if mtype == dhcpv4.MessageTypeNak {
// Set the broadcast bit in the DHCPNAK, so that the relay agent
// broadcasts it to the client, because the client may not have
// a correct network address or subnet mask, and the client may not
// be answering ARP requests.
// broadcasts it to the client, because the client may not have a
// correct network address or subnet mask, and the client may not be
// answering ARP requests.
resp.SetBroadcast()
}
case mtype == dhcpv4.MessageTypeNak:
// Broadcast any DHCPNAK messages to 0xffffffff.
case ciaddr != nil && !ciaddr.IsUnspecified():
// Unicast DHCPOFFER and DHCPACK messages to the address in
// ciaddr.
// Unicast DHCPOFFER and DHCPACK messages to the address in ciaddr.
peer = &net.UDPAddr{
IP: ciaddr,
Port: dhcpv4.ClientPort,
}
case !req.IsBroadcast() && req.ClientHWAddr != nil:
// Unicast DHCPOFFER and DHCPACK messages to the client's
// hardware address and yiaddr.
// Unicast DHCPOFFER and DHCPACK messages to the client's hardware
// address and yiaddr.
peer = &dhcpUnicastAddr{
Addr: raw.Addr{HardwareAddr: req.ClientHWAddr},
yiaddr: resp.YourIPAddr,

View File

@ -247,31 +247,30 @@ func (c *dhcpConn) buildEtherPkt(payload []byte, peer *dhcpUnicastAddr) (pkt []b
func (s *v4Server) send(peer net.Addr, conn net.PacketConn, req, resp *dhcpv4.DHCPv4) {
switch giaddr, ciaddr, mtype := req.GatewayIPAddr, req.ClientIPAddr, resp.MessageType(); {
case giaddr != nil && !giaddr.IsUnspecified():
// Send any return messages to the server port on the BOOTP
// relay agent whose address appears in giaddr.
// Send any return messages to the server port on the BOOTP relay agent
// whose address appears in giaddr.
peer = &net.UDPAddr{
IP: giaddr,
Port: dhcpv4.ServerPort,
}
if mtype == dhcpv4.MessageTypeNak {
// Set the broadcast bit in the DHCPNAK, so that the relay agent
// broadcasts it to the client, because the client may not have
// a correct network address or subnet mask, and the client may not
// be answering ARP requests.
// broadcasts it to the client, because the client may not have a
// correct network address or subnet mask, and the client may not be
// answering ARP requests.
resp.SetBroadcast()
}
case mtype == dhcpv4.MessageTypeNak:
// Broadcast any DHCPNAK messages to 0xffffffff.
case ciaddr != nil && !ciaddr.IsUnspecified():
// Unicast DHCPOFFER and DHCPACK messages to the address in
// ciaddr.
// Unicast DHCPOFFER and DHCPACK messages to the address in ciaddr.
peer = &net.UDPAddr{
IP: ciaddr,
Port: dhcpv4.ClientPort,
}
case !req.IsBroadcast() && req.ClientHWAddr != nil:
// Unicast DHCPOFFER and DHCPACK messages to the client's
// hardware address and yiaddr.
// Unicast DHCPOFFER and DHCPACK messages to the client's hardware
// address and yiaddr.
peer = &dhcpUnicastAddr{
Addr: packet.Addr{HardwareAddr: req.ClientHWAddr},
yiaddr: resp.YourIPAddr,

View File

@ -28,8 +28,9 @@ const (
defaultBackoff time.Duration = 500 * time.Millisecond
)
// Lease contains the necessary information about a DHCP lease. It's used in
// various places. So don't change it without good reason.
// Lease contains the necessary information about a DHCP lease. It's used as is
// in the database, so don't change it until it's absolutely necessary, see
// [dataVersion].
type Lease struct {
// Expiry is the expiration time of the lease.
Expiry time.Time `json:"expires"`
@ -41,8 +42,6 @@ type Lease struct {
HWAddr net.HardwareAddr `json:"mac"`
// IP is the IP address leased to the client.
//
// TODO(a.garipov): Migrate leases.db.
IP netip.Addr `json:"ip"`
// IsStatic defines if the lease is static.

View File

@ -200,7 +200,7 @@ func createICMPv6RAPacket(params icmpv6RA) (data []byte, err error) {
func (ra *raCtx) Init() (err error) {
ra.stop.Store(0)
ra.conn = nil
if !(ra.raAllowSLAAC || ra.raSLAACOnly) {
if !ra.raAllowSLAAC && !ra.raSLAACOnly {
return nil
}

View File

@ -0,0 +1,86 @@
package dhcpsvc
import (
"net/netip"
"time"
"github.com/google/gopacket/layers"
)
// Config is the configuration for the DHCP service.
type Config struct {
// Interfaces stores configurations of DHCP server specific for the network
// interface identified by its name.
Interfaces map[string]*InterfaceConfig
// LocalDomainName is the top-level domain name to use for resolving DHCP
// clients' hostnames.
LocalDomainName string
// ICMPTimeout is the timeout for checking another DHCP server's presence.
ICMPTimeout time.Duration
// Enabled is the state of the service, whether it is enabled or not.
Enabled bool
}
// InterfaceConfig is the configuration of a single DHCP interface.
type InterfaceConfig struct {
// IPv4 is the configuration of DHCP protocol for IPv4.
IPv4 *IPv4Config
// IPv6 is the configuration of DHCP protocol for IPv6.
IPv6 *IPv6Config
}
// IPv4Config is the interface-specific configuration for DHCPv4.
type IPv4Config struct {
// GatewayIP is the IPv4 address of the network's gateway. It is used as
// the default gateway for DHCP clients and also used in calculating the
// network-specific broadcast address.
GatewayIP netip.Addr
// SubnetMask is the IPv4 subnet mask of the network. It should be a valid
// IPv4 subnet mask (i.e. all 1s followed by all 0s).
SubnetMask netip.Addr
// RangeStart is the first address in the range to assign to DHCP clients.
RangeStart netip.Addr
// RangeEnd is the last address in the range to assign to DHCP clients.
RangeEnd netip.Addr
// Options is the list of DHCP options to send to DHCP clients.
Options layers.DHCPOptions
// LeaseDuration is the TTL of a DHCP lease.
LeaseDuration time.Duration
// Enabled is the state of the DHCPv4 service, whether it is enabled or not
// on the specific interface.
Enabled bool
}
// IPv6Config is the interface-specific configuration for DHCPv6.
type IPv6Config struct {
// RangeStart is the first address in the range to assign to DHCP clients.
RangeStart netip.Addr
// Options is the list of DHCP options to send to DHCP clients.
Options layers.DHCPOptions
// LeaseDuration is the TTL of a DHCP lease.
LeaseDuration time.Duration
// RASlaacOnly defines whether the DHCP clients should only use SLAAC for
// address assignment.
RASLAACOnly bool
// RAAllowSlaac defines whether the DHCP clients may use SLAAC for address
// assignment.
RAAllowSLAAC bool
// Enabled is the state of the DHCPv6 service, whether it is enabled or not
// on the specific interface.
Enabled bool
}

120
internal/dhcpsvc/dhcpsvc.go Normal file
View File

@ -0,0 +1,120 @@
// Package dhcpsvc contains the AdGuard Home DHCP service.
//
// TODO(e.burkov): Add tests.
package dhcpsvc
import (
"context"
"net"
"net/netip"
"time"
"github.com/AdguardTeam/AdGuardHome/internal/next/agh"
)
// Lease is a DHCP lease.
//
// TODO(e.burkov): Consider it to [agh], since it also may be needed in
// [websvc]. Also think of implementing iterating methods with appropriate
// signatures.
type Lease struct {
// IP is the IP address leased to the client.
IP netip.Addr
// Expiry is the expiration time of the lease.
Expiry time.Time
// Hostname of the client.
Hostname string
// HWAddr is the physical hardware address (MAC address).
HWAddr net.HardwareAddr
// IsStatic defines if the lease is static.
IsStatic bool
}
type Interface interface {
agh.ServiceWithConfig[*Config]
// Enabled returns true if DHCP provides information about clients.
Enabled() (ok bool)
// HostByIP returns the hostname of the DHCP client with the given IP
// address. The address will be netip.Addr{} if there is no such client,
// due to an assumption that a DHCP client must always have an IP address.
HostByIP(ip netip.Addr) (host string)
// MACByIP returns the MAC address for the given IP address leased. It
// returns nil if there is no such client, due to an assumption that a DHCP
// client must always have a MAC address.
MACByIP(ip netip.Addr) (mac net.HardwareAddr)
// IPByHost returns the IP address of the DHCP client with the given
// hostname. The hostname will be an empty string if there is no such
// client, due to an assumption that a DHCP client must always have a
// hostname, either set by the client or assigned automatically.
IPByHost(host string) (ip netip.Addr)
// Leases returns all the DHCP leases.
Leases() (leases []*Lease)
// AddLease adds a new DHCP lease. It returns an error if the lease is
// invalid or already exists.
AddLease(l *Lease) (err error)
// EditLease changes an existing DHCP lease. It returns an error if there
// is no lease equal to old or if new is invalid or already exists.
EditLease(old, new *Lease) (err error)
// RemoveLease removes an existing DHCP lease. It returns an error if there
// is no lease equal to l.
RemoveLease(l *Lease) (err error)
// Reset removes all the DHCP leases.
Reset() (err error)
}
// Empty is an [Interface] implementation that does nothing.
type Empty struct{}
// type check
var _ Interface = Empty{}
// Start implements the [Service] interface for Empty.
func (Empty) Start() (err error) { return nil }
// Shutdown implements the [Service] interface for Empty.
func (Empty) Shutdown(_ context.Context) (err error) { return nil }
var _ agh.ServiceWithConfig[*Config] = Empty{}
// Config implements the [ServiceWithConfig] interface for Empty.
func (Empty) Config() (conf *Config) { return nil }
// Enabled implements the [Interface] interface for Empty.
func (Empty) Enabled() (ok bool) { return false }
// HostByIP implements the [Interface] interface for Empty.
func (Empty) HostByIP(_ netip.Addr) (host string) { return "" }
// MACByIP implements the [Interface] interface for Empty.
func (Empty) MACByIP(_ netip.Addr) (mac net.HardwareAddr) { return nil }
// IPByHost implements the [Interface] interface for Empty.
func (Empty) IPByHost(_ string) (ip netip.Addr) { return netip.Addr{} }
// Leases implements the [Interface] interface for Empty.
func (Empty) Leases() (leases []*Lease) { return nil }
// AddLease implements the [Interface] interface for Empty.
func (Empty) AddLease(_ *Lease) (err error) { return nil }
// EditLease implements the [Interface] interface for Empty.
func (Empty) EditLease(_, _ *Lease) (err error) { return nil }
// RemoveLease implements the [Interface] interface for Empty.
func (Empty) RemoveLease(_ *Lease) (err error) { return nil }
// Reset implements the [Interface] interface for Empty.
func (Empty) Reset() (err error) { return nil }

View File

@ -48,12 +48,33 @@ var webRegistered bool
// hostToIPTable is a convenient type alias for tables of host names to an IP
// address.
//
// TODO(e.burkov): Use the [DHCP] interface instead.
type hostToIPTable = map[string]netip.Addr
// ipToHostTable is a convenient type alias for tables of IP addresses to their
// host names. For example, for use with PTR queries.
//
// TODO(e.burkov): Use the [DHCP] interface instead.
type ipToHostTable = map[netip.Addr]string
// DHCP is an interface for accesing DHCP lease data needed in this package.
type DHCP interface {
// HostByIP returns the hostname of the DHCP client with the given IP
// address. The address will be netip.Addr{} if there is no such client,
// due to an assumption that a DHCP client must always have an IP address.
HostByIP(ip netip.Addr) (host string)
// IPByHost returns the IP address of the DHCP client with the given
// hostname. The hostname will be an empty string if there is no such
// client, due to an assumption that a DHCP client must always have a
// hostname, either set by the client or assigned automatically.
IPByHost(host string) (ip netip.Addr)
// Enabled returns true if DHCP provides information about clients.
Enabled() (ok bool)
}
// Server is the main way to start a DNS server.
//
// Example:

View File

@ -11,6 +11,7 @@ import (
"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
"github.com/AdguardTeam/AdGuardHome/internal/dhcpsvc"
"github.com/AdguardTeam/AdGuardHome/internal/dnsforward"
"github.com/AdguardTeam/AdGuardHome/internal/filtering"
"github.com/AdguardTeam/AdGuardHome/internal/querylog"
@ -24,6 +25,23 @@ import (
"golang.org/x/exp/slices"
)
// DHCP is an interface for accesing DHCP lease data the [clientsContainer]
// needs.
type DHCP interface {
// Leases returns all the DHCP leases.
Leases() (leases []*dhcpsvc.Lease)
// HostByIP returns the hostname of the DHCP client with the given IP
// address. The address will be netip.Addr{} if there is no such client,
// due to an assumption that a DHCP client must always have an IP address.
HostByIP(ip netip.Addr) (host string)
// MACByIP returns the MAC address for the given IP address leased. It
// returns nil if there is no such client, due to an assumption that a DHCP
// client must always have a MAC address.
MACByIP(ip netip.Addr) (mac net.HardwareAddr)
}
// clientsContainer is the storage of all runtime and persistent clients.
type clientsContainer struct {
// TODO(a.garipov): Perhaps use a number of separate indices for different
@ -101,9 +119,9 @@ func (clients *clientsContainer) Init(
return
}
clients.updateFromDHCP(true)
if clients.dhcpServer != nil {
clients.dhcpServer.SetOnLeaseChanged(clients.onDHCPLeaseChanged)
clients.onDHCPLeaseChanged(dhcpd.LeaseChangedAdded)
}
if clients.etcHosts != nil {
@ -277,15 +295,38 @@ func (clients *clientsContainer) periodicUpdate() {
}
}
// onDHCPLeaseChanged is a callback for the DHCP server. It updates the list of
// runtime clients using the DHCP server's leases.
//
// TODO(e.burkov): Remove when switched to dhcpsvc.
func (clients *clientsContainer) onDHCPLeaseChanged(flags int) {
switch flags {
case dhcpd.LeaseChangedAdded,
dhcpd.LeaseChangedAddedStatic,
dhcpd.LeaseChangedRemovedStatic:
clients.updateFromDHCP(true)
case dhcpd.LeaseChangedRemovedAll:
clients.updateFromDHCP(false)
if clients.dhcpServer == nil || !config.Clients.Sources.DHCP {
return
}
clients.lock.Lock()
defer clients.lock.Unlock()
clients.rmHostsBySrc(ClientSourceDHCP)
if flags == dhcpd.LeaseChangedRemovedAll {
return
}
leases := clients.dhcpServer.Leases(dhcpd.LeasesAll)
n := 0
for _, l := range leases {
if l.Hostname == "" {
continue
}
ok := clients.addHostLocked(l.IP, l.Hostname, ClientSourceDHCP)
if ok {
n++
}
}
log.Debug("clients: added %d client aliases from dhcp", n)
}
// clientSource checks if client with this IP address already exists and returns
@ -301,11 +342,11 @@ func (clients *clientsContainer) clientSource(ip netip.Addr) (src clientSource)
}
rc, ok := clients.ipToRC[ip]
if !ok {
return ClientSourceNone
if ok {
return rc.Source
}
return rc.Source
return ClientSourceNone
}
// findMultiple is a wrapper around Find to make it a valid client finder for
@ -466,11 +507,11 @@ func (clients *clientsContainer) findLocked(id string) (c *Client, ok bool) {
}
}
if clients.dhcpServer == nil {
return nil, false
if clients.dhcpServer != nil {
return clients.findDHCP(ip)
}
return clients.findDHCP(ip)
return nil, false
}
// findDHCP searches for a client by its MAC, if the DHCP server is active and
@ -697,28 +738,27 @@ func (clients *clientsContainer) setWHOISInfo(ip netip.Addr, wi *whois.Info) {
_, ok := clients.findLocked(ip.String())
if ok {
log.Debug("clients: client for %s is already created, ignore whois info", ip)
return
}
// TODO(e.burkov): Consider storing WHOIS information separately and
// potentially get rid of [RuntimeClient].
rc, ok := clients.ipToRC[ip]
if ok {
rc.WHOIS = wi
log.Debug("clients: set whois info for runtime client %s: %+v", rc.Host, wi)
return
}
if !ok {
// Create a RuntimeClient implicitly so that we don't do this check
// again.
rc = &RuntimeClient{
Source: ClientSourceWHOIS,
}
rc.WHOIS = wi
clients.ipToRC[ip] = rc
log.Debug("clients: set whois info for runtime client with ip %s: %+v", ip, wi)
} else {
log.Debug("clients: set whois info for runtime client %s: %+v", rc.Host, wi)
}
rc.WHOIS = wi
}
// AddHost adds a new IP-hostname pairing. The priorities of the sources are
@ -742,22 +782,18 @@ func (clients *clientsContainer) addHostLocked(
src clientSource,
) (ok bool) {
rc, ok := clients.ipToRC[ip]
if ok {
if rc.Source > src {
if !ok {
rc = &RuntimeClient{
WHOIS: &whois.Info{},
}
clients.ipToRC[ip] = rc
} else if src < rc.Source {
return false
}
rc.Host = host
rc.Source = src
} else {
rc = &RuntimeClient{
Host: host,
Source: src,
WHOIS: &whois.Info{},
}
clients.ipToRC[ip] = rc
}
log.Debug("clients: added %s -> %q [%d]", ip, host, len(clients.ipToRC))
@ -827,38 +863,6 @@ func (clients *clientsContainer) addFromSystemARP() {
log.Debug("clients: added %d client aliases from arp neighborhood", added)
}
// updateFromDHCP adds the clients that have a non-empty hostname from the DHCP
// server.
func (clients *clientsContainer) updateFromDHCP(add bool) {
if clients.dhcpServer == nil || !config.Clients.Sources.DHCP {
return
}
clients.lock.Lock()
defer clients.lock.Unlock()
clients.rmHostsBySrc(ClientSourceDHCP)
if !add {
return
}
leases := clients.dhcpServer.Leases(dhcpd.LeasesAll)
n := 0
for _, l := range leases {
if l.Hostname == "" {
continue
}
ok := clients.addHostLocked(l.IP, l.Hostname, ClientSourceDHCP)
if ok {
n++
}
}
log.Debug("clients: added %d client aliases from dhcp", n)
}
// close gracefully closes all the client-specific upstream configurations of
// the persistent clients.
func (clients *clientsContainer) close() (err error) {

View File

@ -228,12 +228,7 @@ func TestRDNS_WorkerLoop(t *testing.T) {
for _, tc := range testCases {
w.Reset()
cc := &clientsContainer{
list: map[string]*Client{},
idIndex: map[string]*Client{},
ipToRC: map[netip.Addr]*RuntimeClient{},
allTags: stringutil.NewSet(),
}
cc := newClientsContainer()
ch := make(chan netip.Addr)
rdns := &RDNS{
exchanger: &rDNSExchanger{